Pool cleaning systems which include a cleaner body adapted to automatically travel through a swimming pool for cleaning debris from the pool water surface and/or containment wall surface are well known. A typical cleaner body is configured to be powered by a positive pressure water flow supplied via a flexible conduit from an electrically powered pump. The supplied water flow is typically directed by a water distribution subsystem carried by the cleaner body to nozzles oriented to discharge water jets to propel the cleaner body along a travel path through the pool. A typical water distribution subsystem functions primarily to propel the cleaner body in a first direction (i.e., forward state) in the pool and to occasionally redirect the cleaner body in a different, or second, direction (i.e., backup/redirect state). Occasional redirection of the cleaner body reduces the likelihood of it getting trapped behind an obstruction in the pool. The prior art also shows cleaning systems configured to cause the body to alternately operate at the water surface (top mode) and at the containment wall surface (bottom mode). Embodiments of such systems are described in various patents including U.S. Pat. Nos. 6,365,039; 7,318,448; 7,501,056.
More particularly, U.S. Pat. No. 6,365,039 describes various positive pressure cleaner embodiments each including a water distribution subsystem for discharging water flows to propel a cleaner body along a substantially random travel path. Such distribution subsystems generally include a valve assembly carried by the cleaner body which, in a forward state, directs a supplied water flow along a first interior path to produce forces on the body for moving it in a first direction or, in a backup/redirect state, along a second interior path to produce forces on the body to redirect it in a second direction different from the first direction. The embodiments described in Patent U.S. Pat. No. 6,365,039 typically employ a valve actuator for controlling a valve element mounted for reciprocal linear movement between first and second positions for respectively directing the supplied water flow along either the first or the second interior path.
U.S. Pat. No. 7,318,448 describes alternative water distribution subsystems employing a piston including a valve element mounted for movement between first and second positions for respectively discharging supplied pressurized water through different discharge jets to respectively propel the cleaner body in a first direction or a second direction.
U.S. Pat. No. 7,501,056 describes further alternative subsystem embodiments for discharging a supplied pressurized water flow through selected discharge jets and characterized by the use of a hydraulic actuator for moving a valve element between different first and second positions.